LPCTSTR lpFileName=L"\\.\Device\Harddisk0\Partition3";
HANDLE handl=CreateFile( lpFileName,
                            GENERIC_READ | GENERIC_WRITE,
                            FILE_SHARE_READ | FILE_SHARE_WRITE,
                            NULL,
                            CREATE_ALWAYS,
                            FILE_ATTRIBUTE_NORMAL,
                            NULL  );
   if (handl==INVALID_HANDLE_VALUE)
   {
   qDebug()<<"handl invalid"<<" error"<<GetLastError();}


   bool success = DefineDosDevice(DDD_RAW_TARGET_PATH,L"I:",L"\Device\Harddisk0\Partition3");
   if(!success)
       qDebug()<<" DefineDosDevice failed "<<GetLastError();


   bFlag = GetVolumeNameForVolumeMountPoint(
               L"I:\", // input volume mount point or directory
               /** what u do in this directory u find it in th mount piont and vice versa**/
                  Buf, // output volume name buffer
              BUFSIZE  // size of volume name buffer
           );
   if (bFlag != TRUE)
   {
      //_tprintf( TEXT("Retrieving volume name for %s failed.n"), argv[2] );
      qDebug()<<"Retrieving volume name failed.      "<<GetLastError();
      return (-2);
   }
    qDebug()<<"Volume name"<<QString::fromWCharArray(Buf);



    bool fResult = DefineDosDevice (
                         DDD_RAW_TARGET_PATH|DDD_REMOVE_DEFINITION|
                         DDD_EXACT_MATCH_ON_REMOVE, L"I:",
                         L"\Device\Harddisk0\Partition3");
    if (!fResult)
                qDebug()<<"DefineDosDevice failed  "<< GetLastError();



   bFlag = SetVolumeMountPoint(L"D:\myDirExample\example\", // mount point
                               /** should b empty**/
                                Buf // volume to be mounted
                               );

   if (!bFlag)
      {
        qDebug()<<"Attempt to mount failed";
        qDebug()<<"error "<<GetLastError();
      }

   return (bFlag);


   CloseHandle(handl);

handl invalid  error 3
Retrieving volume name failed  erorr  2